Selecting a converter operating mode of a PA envelope power supply

1. A radio frequency (RF) communications system comprising:

a power amplifier (PA) envelope power supply adapted to operate in one of a first converter operating mode and a second converter operating mode; and

control circuitry adapted to:

identify a selected communications mode of the RF communications system, a target output power from RF PA circuitry, and a direct current (DC) power supply voltage; and

select one of the first converter operating mode and the second converter operating mode based on the selected communications mode, the target output power, and the DC power supply voltage.

2. The RF communications system of claim 1 wherein:

the PA envelope power supply is further adapted to operate in one of a discontinuous conduction mode (DCM) and a continuous conduction mode (CCM); and

the control circuitry is further adapted to select one of the DCM and the CCM based on the selected communications mode, the target output power, and the DC power supply voltage.

3. The RF communications system of claim 2 wherein the PA envelope power supply is further adapted to have a higher efficiency during the CCM than during the DCM.

4. The RF communications system of claim 2 wherein the control circuitry is further adapted to receive an envelope control signal, such that the PA envelope power supply is not as responsive to certain rapid changes in the envelope control signal during the DCM than during the CCM.

5. The RF communications system of claim 1 wherein the control circuitry is further adapted to receive an envelope control signal, such that the selection of the one of the first converter operating mode and the second converter operating mode is further based on the envelope control signal.

6. The RF communications system of claim 1 further comprising a PA bias power supply having a charge pump wherein:

the charge pump is adapted to operate in one of a bias supply pump-up operating mode and a bias supply bypass operating mode; and

the control circuitry is further adapted to select one of the bias supply pump-up operating mode and the bias supply bypass operating mode based on the selected communications mode, the target output power, and the DC power supply voltage.

7. The RF communications system of claim 6 wherein the PA bias power supply is adapted to provide a bias power supply signal to the RF PA circuitry.

8. The RF communications system of claim 7 wherein the RF PA circuitry is adapted to use the bias power supply signal to provide RF transmit signals.

9. The RF communications system of claim 7 wherein the bias power supply signal has a bias power supply voltage, which is higher during the bias supply pump-up operating mode than during the bias supply bypass operating mode.

10. The RF communications system of claim 6 wherein the PA bias power supply is adapted to operate with higher efficiency during the bias supply bypass operating mode than during the bias supply pump-up operating mode.

11. The RF communications system of claim 1 wherein the PA envelope power supply is further adapted to provide an envelope power supply signal to the RF PA circuitry, which is adapted to use the envelope power supply signal to provide RF transmit signals.

12. The RF communications system of claim 11 further comprising the RF PA circuitry.

13. The RF communications system of claim 11 wherein the envelope power supply signal has an envelope power supply voltage, which is higher during the first converter operating mode than during the second converter operating mode.

14. The RF communications system of claim 11 wherein the PA envelope power supply is further adapted to receive a DC power supply signal, which has the DC power supply voltage, and provide the envelope power supply signal based on DC-DC conversion of the DC power supply signal.

15. The RF communications system of claim 1 wherein the PA envelope power supply is further adapted to operate with higher efficiency during the second converter operating mode than during the first converter operating mode.

16. The RF communications system of claim 1 wherein the PA envelope power supply comprises a charge pump buck converter and a buck converter, such that:

during the first converter operating mode, the charge pump buck converter is active; and

during the second converter operating mode, the buck converter is active.

17. The RF communications system of claim 16 wherein:

during the first converter operating mode, the buck converter is inactive; and

during the second converter operating mode, the charge pump buck converter is inactive.

18. The RF communications system of claim 1 further comprising the RF PA circuitry, which comprises:

a first RF PA comprising:

a first non-quadrature PA path having a first single-ended output; and

a first quadrature PA path coupled between the first non-quadrature PA path and an antenna port, such that the first quadrature PA path has a first single-ended input, which is coupled to the first single-ended output; and

a second RF PA comprising a second quadrature PA path coupled to the antenna port,

wherein the antenna port is configured to be coupled to an antenna.

19. The RF communications system of claim 1 further comprising the RF PA circuitry, which comprises:

a first multi-mode multi-band quadrature RF PA coupled to multi-mode multi-band alpha switching circuitry via a single alpha PA output; and

the multi-mode multi-band alpha switching circuitry having:

a first alpha non-linear mode output associated with a first non-linear mode RF communications band; and

a plurality of alpha linear mode outputs, such that each of the plurality of alpha linear mode outputs is associated with a corresponding one of a first plurality of linear mode RF communications bands.

20. The RF communications system of claim 1 further comprising the RF PA circuitry, which comprises:

a first RF PA comprising a first final stage having a first final bias input, such that bias of the first final stage is via the first final bias input;

PA control circuitry;

a PA-digital communications interface (DCI) coupled between a digital communications bus and the PA control circuitry; and

a final stage current digital-to-analog converter (IDAC) coupled between the PA control circuitry and the first final bias input.

21. The RF communications system of claim 1 further comprising:

a first RF PA of the RF PA circuitry and having a first final stage and adapted to:

receive and amplify a first RF input signal to provide a first RF output signal; and

receive a first final bias signal to bias the first final stage;

PA bias circuitry of the RF PA circuitry and adapted to receive a bias power supply signal and provide the first final bias signal based on the bias power supply signal; and

a DC-DC converter adapted to receive a DC power supply signal from a DC power supply and provide the bias power supply signal based on the DC power supply signal, such that a voltage of the bias power supply signal is greater than a voltage of the DC power supply signal.

22. The RF communications system of claim 1 further comprising:

a DC-DC converter comprising:

the PA envelope power supply comprising a charge pump buck converter coupled to the RF PA circuitry; and

a PA bias power supply comprising a charge pump coupled to the RF PA circuitry; and

the RF PA circuitry.

23. The RF communications system of claim 1 further comprising the RF PA circuitry, which comprises:

multi-mode multi-band RF power amplification circuitry having at least a first RF input and a plurality of RF outputs, such that:

configuration of the multi-mode multi-band RF power amplification circuitry associates one of the at least the first RF input with one of the plurality of RF outputs; and

the configuration is associated with at least a first look-up table (LUT);

PA control circuitry coupled between the multi-mode multi-band RF power amplification circuitry and a PA-digital communications interface (DCI), such that the PA control circuitry has at least the first LUT, which is associated with at least a first defined parameter set; and

the PA-DCI, which is coupled to a digital communications bus.

24. A method comprising:

providing a power amplifier (PA) envelope power supply and control circuitry;

identifying a selected communications mode of a radio frequency (RF) communications system, a target output power from RF PA circuitry, and a direct current (DC) power supply voltage; and

selecting one of a first converter operating mode and a second converter operating mode of the PA envelope power supply based on the selected communications mode, the target output power, and the DC power supply voltage.

25. The method of claim 24 further comprising selecting one of a discontinuous conduction mode (DCM) and a continuous conduction mode (CCM) of the PA envelope power supply based on the selected communications mode, the target output power, and the DC power supply voltage.

26. The method of claim 24 further comprising selecting one of a bias supply pump-up operating mode and a bias supply bypass operating mode of a charge pump of a PA bias power supply based on the selected communications mode, the target output power, and the DC power supply voltage.